Bridget Koontz, MD, outlines trial of ADT plus SBRT in oligometastatic prostate cancer

In this video, Bridget F. Koontz, MD, FASTRO, highlights the design and enrollment criteria of the ongoing phase 2 NRG-GU011 trial (NCT05053152), which is assessing the combination of relugolix plus stereotactic body radiation therapy (SBRT) vs SBRT alone in patients with PET-oligometastatic prostate cancer. The trial is currently seeking enrollment.

Koontz is radiation oncologist and the medical director of radiation oncology programs at AdventHealth Cancer Institute in Orlando, Florida.

Video Transcript:

How is the study designed?

The study is a phase 2 randomized design. It's 1:1, patients receiving radiotherapy or radiotherapy with relugolix. It is a placebo-controlled trial, because in addition to the primary end point, which is conventional imaging progression-free survival, our secondary end points include a lot of quality-of-life patient-reported outcomes. So, we do blind both patients and their treating providers to whether or not they're on investigational drug. That allows us to gather side effect profiles of these treatments, trying to minimize the placebo effect.

We are also looking at [other] traditional cancer end points of biochemical recurrence after therapy, additional treatments that are needed after the study protocol therapy, [and] PET-based progression, which I think is going to be a very important end point, but it's not yet correlated to overall survival, which is why we're looking at traditional metastatic disease-free survival as our primary [end point]. I think [there's] a lot of data that's going to come out of this in terms of how we treat men. My hope is that when this study is over [and] the hypothesis is that we'll find that with relugolix, there's an improved progression-free survival, but we'll also have quality of life data. So, [to] that patient sitting in front of me in the office, I'll be able to say, "This is the benefit of starting ADT. I know you're worried about ADT; this is what to expect from a side effect profile," and that way men can make their own decision. How much do they value delaying progression? How much do they value hormonal quality of life? That allows our patients to make good, evidence-based decisions about their care.

What are the enrollment criteria for this trial?

This is a PSA recurrent setting. Patients have already had previous treatment to their prostate, whether that be prostatectomy [or] radiation. If they've had a prostatectomy, they may have had previous radiation to the prostate bed, [or] they may not. They're allowed to have had previous hormone therapy, but it's really one of the key criteria for enrollment. What has been a challenge for us is that we need them to have at least recovered their testosterone to 100 ng/dL. The reason for that, again, is the side effects that we want to be able to track and measure so we're giving patients good quality information about the risks and the benefits of these 2 approaches. Other than that, it's just that they [have] PET metastatic disease.

I think the challenge is in whether or not to start somebody on hormone therapy with a PET-positive scan, but it's really, otherwise a pretty open study. We're looking for folks who can safely get SBRT, so if they've had previous radiation at the site of their recurrent disease, that doesn't make a lot of sense. We don't want to be treating those folks on a study. We want to be able to modify the treatment for safety purposes, but otherwise it's pretty straightforward: PSA progression, metastatic disease, and a testosterone that shows that they're not castration resistant.

This transcription has been edited for clarity.